a natural process resulting in the evolution of organisms best adapted to the environment
inherited characteristic that increases an organism's chance of survival
similar structure found in more than one species that share a common ancestor
remnant of a structure that may have had an important function in a species' ancestors, but has no clear function in the modern species
formation of new species
well-tested explanation that unifies a broad range of observations
pattern of evolution in which long stable periods are interrupted by brief periods of more rapid change
The theory that evolution occurs slowly but steadily.
the resemblance of an animal species to another species or to natural objects
coloration that blends in with the surrounding environment for survival purposes
Accumulation of differences between groups; can lead to the formation of new species.